/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.coders;



import com.bff.gaia.unified.sdk.values.TypeDescriptor;

import com.bff.gaia.unified.sdk.values.TypeParameter;



import java.util.HashSet;

import java.util.List;

import java.util.Set;



/**

 * A {@link SetCoder} encodes any {@link Set} using the format of {@link IterableLikeCoder}. The

 * elements may not be in a deterministic order, depending on the {@code Set} implementation.

 *

 * @param <T> the type of the elements of the set

 */

public class SetCoder<T> extends IterableLikeCoder<T, Set<T>> {



  /** Produces a {@link SetCoder} with the given {@code elementCoder}. */

  public static <T> SetCoder<T> of(Coder<T> elementCoder) {

    return new SetCoder<>(elementCoder);

  }



  /**

   * {@inheritDoc}

   *

   * @throws Coder.NonDeterministicException always. Sets are not ordered, but they are encoded in the

   *     order of an arbitrary iteration.

   */

  @Override

  public void verifyDeterministic() throws Coder.NonDeterministicException {

    throw new Coder.NonDeterministicException(

        this, "Ordering of elements in a set may be non-deterministic.");

  }



  @Override

  public TypeDescriptor<Set<T>> getEncodedTypeDescriptor() {

    return new TypeDescriptor<Set<T>>() {}.where(

        new TypeParameter<T>() {}, getElemCoder().getEncodedTypeDescriptor());

  }



  /////////////////////////////////////////////////////////////////////////////

  // Internal operations below here.



  /**

   * {@inheritDoc}

   *

   * @return A new {@link Set} built from the elements in the {@link List} decoded by {@link

   *     IterableLikeCoder}.

   */

  @Override

  protected final Set<T> decodeToIterable(List<T> decodedElements) {

    return new HashSet<>(decodedElements);

  }



  protected SetCoder(Coder<T> elemCoder) {

    super(elemCoder, "Set");

  }

}